IPv4 Subnet Calculator

This calculator and tool allows you to type an IP address in and get information on a particular subnet. Enter an IP or range in CIDR notation.

Network: 9.128.56.0/21
Addresses: 2048 (2¹¹)
First IP: 9.128.56.0 (0.56.128.9.in-addr.arpa)
Last IP: 9.128.63.255 (255.63.128.9.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

9.0.0.0/8
8.0.0.0/8
10.0.0.0/8
9.128.48.0/20
9.128.56.0/32
9.128.63.255/32

You can also use some of the other examples such as:

0.0.0.0/0
1.0.0.0/8
127.0.0.1
30.0.0.0/8
192.168.0.0/16